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path: root/drivers/target/loopback/tcm_loop.c
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Diffstat (limited to 'drivers/target/loopback/tcm_loop.c')
-rw-r--r--drivers/target/loopback/tcm_loop.c363
1 files changed, 159 insertions, 204 deletions
diff --git a/drivers/target/loopback/tcm_loop.c b/drivers/target/loopback/tcm_loop.c
index c47ff7f59e5..a9b4eeefe9f 100644
--- a/drivers/target/loopback/tcm_loop.c
+++ b/drivers/target/loopback/tcm_loop.c
@@ -44,138 +44,12 @@
/* Local pointer to allocated TCM configfs fabric module */
static struct target_fabric_configfs *tcm_loop_fabric_configfs;
+static struct workqueue_struct *tcm_loop_workqueue;
static struct kmem_cache *tcm_loop_cmd_cache;
static int tcm_loop_hba_no_cnt;
-/*
- * Allocate a tcm_loop cmd descriptor from target_core_mod code
- *
- * Can be called from interrupt context in tcm_loop_queuecommand() below
- */
-static struct se_cmd *tcm_loop_allocate_core_cmd(
- struct tcm_loop_hba *tl_hba,
- struct se_portal_group *se_tpg,
- struct scsi_cmnd *sc)
-{
- struct se_cmd *se_cmd;
- struct se_session *se_sess;
- struct tcm_loop_nexus *tl_nexus = tl_hba->tl_nexus;
- struct tcm_loop_cmd *tl_cmd;
- int sam_task_attr;
-
- if (!tl_nexus) {
- scmd_printk(KERN_ERR, sc, "TCM_Loop I_T Nexus"
- " does not exist\n");
- set_host_byte(sc, DID_ERROR);
- return NULL;
- }
- se_sess = tl_nexus->se_sess;
-
- tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_ATOMIC);
- if (!tl_cmd) {
- pr_err("Unable to allocate struct tcm_loop_cmd\n");
- set_host_byte(sc, DID_ERROR);
- return NULL;
- }
- se_cmd = &tl_cmd->tl_se_cmd;
- /*
- * Save the pointer to struct scsi_cmnd *sc
- */
- tl_cmd->sc = sc;
- /*
- * Locate the SAM Task Attr from struct scsi_cmnd *
- */
- if (sc->device->tagged_supported) {
- switch (sc->tag) {
- case HEAD_OF_QUEUE_TAG:
- sam_task_attr = MSG_HEAD_TAG;
- break;
- case ORDERED_QUEUE_TAG:
- sam_task_attr = MSG_ORDERED_TAG;
- break;
- default:
- sam_task_attr = MSG_SIMPLE_TAG;
- break;
- }
- } else
- sam_task_attr = MSG_SIMPLE_TAG;
-
- /*
- * Initialize struct se_cmd descriptor from target_core_mod infrastructure
- */
- transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
- scsi_bufflen(sc), sc->sc_data_direction, sam_task_attr,
- &tl_cmd->tl_sense_buf[0]);
-
- if (scsi_bidi_cmnd(sc))
- se_cmd->se_cmd_flags |= SCF_BIDI;
-
- /*
- * Locate the struct se_lun pointer and attach it to struct se_cmd
- */
- if (transport_lookup_cmd_lun(se_cmd, tl_cmd->sc->device->lun) < 0) {
- kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
- set_host_byte(sc, DID_NO_CONNECT);
- return NULL;
- }
-
- return se_cmd;
-}
-
-/*
- * Called by struct target_core_fabric_ops->new_cmd_map()
- *
- * Always called in process context. A non zero return value
- * here will signal to handle an exception based on the return code.
- */
-static int tcm_loop_new_cmd_map(struct se_cmd *se_cmd)
-{
- struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
- struct tcm_loop_cmd, tl_se_cmd);
- struct scsi_cmnd *sc = tl_cmd->sc;
- struct scatterlist *sgl_bidi = NULL;
- u32 sgl_bidi_count = 0;
- int ret;
- /*
- * Allocate the necessary tasks to complete the received CDB+data
- */
- ret = transport_generic_allocate_tasks(se_cmd, sc->cmnd);
- if (ret != 0)
- return ret;
- /*
- * For BIDI commands, pass in the extra READ buffer
- * to transport_generic_map_mem_to_cmd() below..
- */
- if (se_cmd->se_cmd_flags & SCF_BIDI) {
- struct scsi_data_buffer *sdb = scsi_in(sc);
-
- sgl_bidi = sdb->table.sgl;
- sgl_bidi_count = sdb->table.nents;
- }
- /*
- * Because some userspace code via scsi-generic do not memset their
- * associated read buffers, go ahead and do that here for type
- * SCF_SCSI_CONTROL_SG_IO_CDB. Also note that this is currently
- * guaranteed to be a single SGL for SCF_SCSI_CONTROL_SG_IO_CDB
- * by target core in transport_generic_allocate_tasks() ->
- * transport_generic_cmd_sequencer().
- */
- if (se_cmd->se_cmd_flags & SCF_SCSI_CONTROL_SG_IO_CDB &&
- se_cmd->data_direction == DMA_FROM_DEVICE) {
- struct scatterlist *sg = scsi_sglist(sc);
- unsigned char *buf = kmap(sg_page(sg)) + sg->offset;
-
- if (buf != NULL) {
- memset(buf, 0, sg->length);
- kunmap(sg_page(sg));
- }
- }
-
- /* Tell the core about our preallocated memory */
- return transport_generic_map_mem_to_cmd(se_cmd, scsi_sglist(sc),
- scsi_sg_count(sc), sgl_bidi, sgl_bidi_count);
-}
+static int tcm_loop_queue_status(struct se_cmd *se_cmd);
/*
* Called from struct target_core_fabric_ops->check_stop_free()
@@ -187,7 +61,7 @@ static int tcm_loop_check_stop_free(struct se_cmd *se_cmd)
* pointer. These will be released directly in tcm_loop_device_reset()
* with transport_generic_free_cmd().
*/
- if (se_cmd->se_tmr_req)
+ if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
return 0;
/*
* Release the struct se_cmd, which will make a callback to release
@@ -263,50 +137,152 @@ static int tcm_loop_change_queue_depth(
}
/*
- * Main entry point from struct scsi_host_template for incoming SCSI CDB+Data
- * from Linux/SCSI subsystem for SCSI low level device drivers (LLDs)
+ * Locate the SAM Task Attr from struct scsi_cmnd *
*/
-static int tcm_loop_queuecommand(
- struct Scsi_Host *sh,
- struct scsi_cmnd *sc)
+static int tcm_loop_sam_attr(struct scsi_cmnd *sc)
{
- struct se_cmd *se_cmd;
- struct se_portal_group *se_tpg;
+ if (sc->device->tagged_supported) {
+ switch (sc->tag) {
+ case HEAD_OF_QUEUE_TAG:
+ return MSG_HEAD_TAG;
+ case ORDERED_QUEUE_TAG:
+ return MSG_ORDERED_TAG;
+ default:
+ break;
+ }
+ }
+
+ return MSG_SIMPLE_TAG;
+}
+
+static void tcm_loop_submission_work(struct work_struct *work)
+{
+ struct tcm_loop_cmd *tl_cmd =
+ container_of(work, struct tcm_loop_cmd, work);
+ struct se_cmd *se_cmd = &tl_cmd->tl_se_cmd;
+ struct scsi_cmnd *sc = tl_cmd->sc;
+ struct tcm_loop_nexus *tl_nexus;
struct tcm_loop_hba *tl_hba;
struct tcm_loop_tpg *tl_tpg;
+ struct scatterlist *sgl_bidi = NULL;
+ u32 sgl_bidi_count = 0;
+ int ret;
- pr_debug("tcm_loop_queuecommand() %d:%d:%d:%d got CDB: 0x%02x"
- " scsi_buf_len: %u\n", sc->device->host->host_no,
- sc->device->id, sc->device->channel, sc->device->lun,
- sc->cmnd[0], scsi_bufflen(sc));
- /*
- * Locate the tcm_loop_hba_t pointer
- */
tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
+
/*
* Ensure that this tl_tpg reference from the incoming sc->device->id
* has already been configured via tcm_loop_make_naa_tpg().
*/
if (!tl_tpg->tl_hba) {
set_host_byte(sc, DID_NO_CONNECT);
- sc->scsi_done(sc);
- return 0;
+ goto out_done;
}
- se_tpg = &tl_tpg->tl_se_tpg;
+
+ tl_nexus = tl_hba->tl_nexus;
+ if (!tl_nexus) {
+ scmd_printk(KERN_ERR, sc, "TCM_Loop I_T Nexus"
+ " does not exist\n");
+ set_host_byte(sc, DID_ERROR);
+ goto out_done;
+ }
+
+ transport_init_se_cmd(se_cmd, tl_tpg->tl_se_tpg.se_tpg_tfo,
+ tl_nexus->se_sess,
+ scsi_bufflen(sc), sc->sc_data_direction,
+ tcm_loop_sam_attr(sc), &tl_cmd->tl_sense_buf[0]);
+
+ if (scsi_bidi_cmnd(sc)) {
+ struct scsi_data_buffer *sdb = scsi_in(sc);
+
+ sgl_bidi = sdb->table.sgl;
+ sgl_bidi_count = sdb->table.nents;
+ se_cmd->se_cmd_flags |= SCF_BIDI;
+
+ }
+
+ if (transport_lookup_cmd_lun(se_cmd, tl_cmd->sc->device->lun) < 0) {
+ kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
+ set_host_byte(sc, DID_NO_CONNECT);
+ goto out_done;
+ }
+
/*
- * Determine the SAM Task Attribute and allocate tl_cmd and
- * tl_cmd->tl_se_cmd from TCM infrastructure
+ * Because some userspace code via scsi-generic do not memset their
+ * associated read buffers, go ahead and do that here for type
+ * SCF_SCSI_CONTROL_SG_IO_CDB. Also note that this is currently
+ * guaranteed to be a single SGL for SCF_SCSI_CONTROL_SG_IO_CDB
+ * by target core in transport_generic_allocate_tasks() ->
+ * transport_generic_cmd_sequencer().
*/
- se_cmd = tcm_loop_allocate_core_cmd(tl_hba, se_tpg, sc);
- if (!se_cmd) {
+ if (se_cmd->se_cmd_flags & SCF_SCSI_CONTROL_SG_IO_CDB &&
+ se_cmd->data_direction == DMA_FROM_DEVICE) {
+ struct scatterlist *sg = scsi_sglist(sc);
+ unsigned char *buf = kmap(sg_page(sg)) + sg->offset;
+
+ if (buf != NULL) {
+ memset(buf, 0, sg->length);
+ kunmap(sg_page(sg));
+ }
+ }
+
+ ret = transport_generic_allocate_tasks(se_cmd, sc->cmnd);
+ if (ret == -ENOMEM) {
+ transport_send_check_condition_and_sense(se_cmd,
+ TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0);
+ transport_generic_free_cmd(se_cmd, 0);
+ return;
+ } else if (ret < 0) {
+ if (se_cmd->se_cmd_flags & SCF_SCSI_RESERVATION_CONFLICT)
+ tcm_loop_queue_status(se_cmd);
+ else
+ transport_send_check_condition_and_sense(se_cmd,
+ se_cmd->scsi_sense_reason, 0);
+ transport_generic_free_cmd(se_cmd, 0);
+ return;
+ }
+
+ ret = transport_generic_map_mem_to_cmd(se_cmd, scsi_sglist(sc),
+ scsi_sg_count(sc), sgl_bidi, sgl_bidi_count);
+ if (ret) {
+ transport_send_check_condition_and_sense(se_cmd,
+ se_cmd->scsi_sense_reason, 0);
+ transport_generic_free_cmd(se_cmd, 0);
+ return;
+ }
+ transport_handle_cdb_direct(se_cmd);
+ return;
+
+out_done:
+ sc->scsi_done(sc);
+ return;
+}
+
+/*
+ * ->queuecommand can be and usually is called from interrupt context, so
+ * defer the actual submission to a workqueue.
+ */
+static int tcm_loop_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *sc)
+{
+ struct tcm_loop_cmd *tl_cmd;
+
+ pr_debug("tcm_loop_queuecommand() %d:%d:%d:%d got CDB: 0x%02x"
+ " scsi_buf_len: %u\n", sc->device->host->host_no,
+ sc->device->id, sc->device->channel, sc->device->lun,
+ sc->cmnd[0], scsi_bufflen(sc));
+
+ tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_ATOMIC);
+ if (!tl_cmd) {
+ pr_err("Unable to allocate struct tcm_loop_cmd\n");
+ set_host_byte(sc, DID_ERROR);
sc->scsi_done(sc);
return 0;
}
- /*
- * Queue up the newly allocated to be processed in TCM thread context.
- */
- transport_generic_handle_cdb_map(se_cmd);
+
+ tl_cmd->sc = sc;
+ INIT_WORK(&tl_cmd->work, tcm_loop_submission_work);
+ queue_work(tcm_loop_workqueue, &tl_cmd->work);
return 0;
}
@@ -324,7 +300,7 @@ static int tcm_loop_device_reset(struct scsi_cmnd *sc)
struct tcm_loop_nexus *tl_nexus;
struct tcm_loop_tmr *tl_tmr = NULL;
struct tcm_loop_tpg *tl_tpg;
- int ret = FAILED;
+ int ret = FAILED, rc;
/*
* Locate the tcm_loop_hba_t pointer
*/
@@ -365,12 +341,9 @@ static int tcm_loop_device_reset(struct scsi_cmnd *sc)
transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess, 0,
DMA_NONE, MSG_SIMPLE_TAG,
&tl_cmd->tl_sense_buf[0]);
- /*
- * Allocate the LUN_RESET TMR
- */
- se_cmd->se_tmr_req = core_tmr_alloc_req(se_cmd, tl_tmr,
- TMR_LUN_RESET, GFP_KERNEL);
- if (IS_ERR(se_cmd->se_tmr_req))
+
+ rc = core_tmr_alloc_req(se_cmd, tl_tmr, TMR_LUN_RESET, GFP_KERNEL);
+ if (rc < 0)
goto release;
/*
* Locate the underlying TCM struct se_lun from sc->device->lun
@@ -762,22 +735,6 @@ static u32 tcm_loop_get_inst_index(struct se_portal_group *se_tpg)
return 1;
}
-static int tcm_loop_is_state_remove(struct se_cmd *se_cmd)
-{
- /*
- * Assume struct scsi_cmnd is not in remove state..
- */
- return 0;
-}
-
-static int tcm_loop_sess_logged_in(struct se_session *se_sess)
-{
- /*
- * Assume that TL Nexus is always active
- */
- return 1;
-}
-
static u32 tcm_loop_sess_get_index(struct se_session *se_sess)
{
return 1;
@@ -811,19 +768,6 @@ static void tcm_loop_close_session(struct se_session *se_sess)
return;
};
-static void tcm_loop_stop_session(
- struct se_session *se_sess,
- int sess_sleep,
- int conn_sleep)
-{
- return;
-}
-
-static void tcm_loop_fall_back_to_erl0(struct se_session *se_sess)
-{
- return;
-}
-
static int tcm_loop_write_pending(struct se_cmd *se_cmd)
{
/*
@@ -855,6 +799,9 @@ static int tcm_loop_queue_data_in(struct se_cmd *se_cmd)
sc->result = SAM_STAT_GOOD;
set_host_byte(sc, DID_OK);
+ if ((se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT) ||
+ (se_cmd->se_cmd_flags & SCF_UNDERFLOW_BIT))
+ scsi_set_resid(sc, se_cmd->residual_count);
sc->scsi_done(sc);
return 0;
}
@@ -880,6 +827,9 @@ static int tcm_loop_queue_status(struct se_cmd *se_cmd)
sc->result = se_cmd->scsi_status;
set_host_byte(sc, DID_OK);
+ if ((se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT) ||
+ (se_cmd->se_cmd_flags & SCF_UNDERFLOW_BIT))
+ scsi_set_resid(sc, se_cmd->residual_count);
sc->scsi_done(sc);
return 0;
}
@@ -1361,7 +1311,6 @@ static struct configfs_attribute *tcm_loop_wwn_attrs[] = {
static int tcm_loop_register_configfs(void)
{
struct target_fabric_configfs *fabric;
- struct config_group *tf_cg;
int ret;
/*
* Set the TCM Loop HBA counter to zero
@@ -1407,14 +1356,10 @@ static int tcm_loop_register_configfs(void)
/*
* Used for setting up remaining TCM resources in process context
*/
- fabric->tf_ops.new_cmd_map = &tcm_loop_new_cmd_map;
fabric->tf_ops.check_stop_free = &tcm_loop_check_stop_free;
fabric->tf_ops.release_cmd = &tcm_loop_release_cmd;
fabric->tf_ops.shutdown_session = &tcm_loop_shutdown_session;
fabric->tf_ops.close_session = &tcm_loop_close_session;
- fabric->tf_ops.stop_session = &tcm_loop_stop_session;
- fabric->tf_ops.fall_back_to_erl0 = &tcm_loop_fall_back_to_erl0;
- fabric->tf_ops.sess_logged_in = &tcm_loop_sess_logged_in;
fabric->tf_ops.sess_get_index = &tcm_loop_sess_get_index;
fabric->tf_ops.sess_get_initiator_sid = NULL;
fabric->tf_ops.write_pending = &tcm_loop_write_pending;
@@ -1431,9 +1376,7 @@ static int tcm_loop_register_configfs(void)
fabric->tf_ops.queue_tm_rsp = &tcm_loop_queue_tm_rsp;
fabric->tf_ops.set_fabric_sense_len = &tcm_loop_set_fabric_sense_len;
fabric->tf_ops.get_fabric_sense_len = &tcm_loop_get_fabric_sense_len;
- fabric->tf_ops.is_state_remove = &tcm_loop_is_state_remove;
- tf_cg = &fabric->tf_group;
/*
* Setup function pointers for generic logic in target_core_fabric_configfs.c
*/
@@ -1490,7 +1433,11 @@ static void tcm_loop_deregister_configfs(void)
static int __init tcm_loop_fabric_init(void)
{
- int ret;
+ int ret = -ENOMEM;
+
+ tcm_loop_workqueue = alloc_workqueue("tcm_loop", 0, 0);
+ if (!tcm_loop_workqueue)
+ goto out;
tcm_loop_cmd_cache = kmem_cache_create("tcm_loop_cmd_cache",
sizeof(struct tcm_loop_cmd),
@@ -1499,20 +1446,27 @@ static int __init tcm_loop_fabric_init(void)
if (!tcm_loop_cmd_cache) {
pr_debug("kmem_cache_create() for"
" tcm_loop_cmd_cache failed\n");
- return -ENOMEM;
+ goto out_destroy_workqueue;
}
ret = tcm_loop_alloc_core_bus();
if (ret)
- return ret;
+ goto out_destroy_cache;
ret = tcm_loop_register_configfs();
- if (ret) {
- tcm_loop_release_core_bus();
- return ret;
- }
+ if (ret)
+ goto out_release_core_bus;
return 0;
+
+out_release_core_bus:
+ tcm_loop_release_core_bus();
+out_destroy_cache:
+ kmem_cache_destroy(tcm_loop_cmd_cache);
+out_destroy_workqueue:
+ destroy_workqueue(tcm_loop_workqueue);
+out:
+ return ret;
}
static void __exit tcm_loop_fabric_exit(void)
@@ -1520,6 +1474,7 @@ static void __exit tcm_loop_fabric_exit(void)
tcm_loop_deregister_configfs();
tcm_loop_release_core_bus();
kmem_cache_destroy(tcm_loop_cmd_cache);
+ destroy_workqueue(tcm_loop_workqueue);
}
MODULE_DESCRIPTION("TCM loopback virtual Linux/SCSI fabric module");